Prediction of preterm birth and adverse perinatal outcomes after cervical pessary placement in singleton pregnancies with short cervical length.

Transvaginal ultrasound after pessary placement detects incorrect pessary placement after pessary insertion and during follow-up. APO and sPTB can be predicted by measuring CL, A-UCA, CLCI, and ISA immediately after pessary placement, being CL and A-UCA more accurate and easier to be measured. Our results help to better identify women in whom the pessary is more likely to fail. Further research is required to assess the effectiveness of applying alternative, sequential or additional treatments to reduce prematurity and our results could be considered when designing such studies.